Method for producing olefin compounds using iron-containing oxygen carrier materials

Abstract

Olefin compounds can be produced by a method comprising: passing a feed stream into a reactor, wherein the feed stream may contain one or more hydrocarbons; and passing an oxygen carrier material into the reactor. In the reactor, the one or more hydrocarbons may be dehydrogenated to form hydrogen and one or more olefin compounds, and at least a portion of the hydrogen may be reacted with oxygen from the oxygen carrier material to produce water. The oxygen carrier material may comprise a first composition. At least 95% by weight of the first composition may consist of: 1 mole of iron; 0.04 to 0.8 moles of one or more alkali metals; 0.02 to 0.4 moles of tungsten; 0 to 3 moles of titanium; and 1 to 10 moles of oxygen.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 595,986, filed November 3, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] The embodiments disclosed herein generally relate to chemical processing, and specifically to chemical processing for the production of olefin materials. Background Technology

[0003] Olefin compounds, such as light olefins (e.g., ethylene, butene, and propylene), can be used as base materials to produce a wide variety of materials, such as polyethylene, polypropylene, isopropanol, and acrylic acid, which can be used in, for example, packaging, construction, and textiles. As a result of this utility, there is a global demand for light olefins. Suitable processes for producing light olefins generally depend on the given chemical feedstock and include those utilizing fluidized bed catalysts. For example, light olefins can be formed by the catalytic dehydrogenation of alkanes in a fluidized bed reactor. However, there is a need to improve the methods for preparing light olefins. Summary of the Invention

[0004] There is a persistent need for methods for producing olefin compounds. This document describes a method for producing olefin compounds by means of a process that typically includes the formation of olefin compounds through the dehydrogenation of hydrocarbons, such as alkanes. In such embodiments, an oxygen carrier material can be utilized, which supplies oxygen to burn hydrogen formed by the dehydrogenation reaction. Burning hydrogen typically shifts the dehydrogenation equilibrium toward the products (hydrogen and olefin compounds). It has been found that certain oxygen carrier materials described herein are well-suited for this process due to their relatively high selectivity for burning hydrogen compared to burning hydrocarbons. Specifically, as described herein, oxygen carrier materials containing at least iron, one or more alkali metals, tungsten, and oxygen in specific amounts relative to each other can exhibit such selectivity and are well-suited for the methods described herein.

[0005] According to one or more embodiments of this disclosure, olefin compounds can be produced by a method comprising: passing a feed stream into a reactor, wherein the feed stream contains one or more hydrocarbons; and passing an oxygen carrier material into the reactor. In the reactor, one or more hydrocarbons can be dehydrogenated to form hydrogen and one or more olefin compounds, and at least a portion of the hydrogen can be reacted with oxygen from the oxygen carrier material to produce water. The oxygen carrier material may comprise a first composition. At least 95% by weight of the first composition may consist of: 1 mole of iron; 0.04 to 0.8 moles of one or more alkali metals; 0.02 to 0.4 moles of tungsten; 0 to 3 moles of titanium; and 1 to 10 moles of oxygen.

[0006] Additional features and advantages of this disclosure will be set forth in the detailed description below, and will be partly apparent from the description or by practice of the embodiments described herein, including the detailed description below, the claims, and the drawings. Attached Figure Description

[0007] The following detailed description of specific embodiments of this disclosure is best understood in conjunction with the following drawings, in which similar reference numerals indicate similar structures and in the drawings:

[0008] Figure 1 This is a schematic diagram of a reactor system suitable for use with an oxygen carrier material according to one or more embodiments described herein.

[0009] Additional features and advantages of this disclosure will be set forth in the detailed description below, and will be partly apparent from the description or by practice of the embodiments described herein, including the detailed description below, the claims, and the drawings.

[0010] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. Drawings are included to provide a further understanding of the various embodiments, and these drawings are incorporated in and form a part of this specification. The drawings illustrate the various embodiments described herein and, together with the specification, explain the principles and operation of the claimed subject matter. Detailed Implementation

[0011] Specific embodiments of this application will now be described. However, the technical aspects of this application may be implemented in different forms and should not be construed as limited to the embodiments described in this specific embodiment.

[0012] Generally, various embodiments of methods for producing olefin compounds are described in this disclosure. According to one or more embodiments of this disclosure, the methods for producing olefin compounds utilize oxygen carrier materials (sometimes simply referred to herein as "oxygen carriers") described herein. For example, the process may utilize an oxygen carrier material comprising at least iron, oxygen, one or more alkali metals, and tungsten.

[0013] As used herein, the term "olefin compound" refers to a hydrocarbon having one or more carbon-carbon double bonds, other than the formal double bonds found in aromatic compounds. For example, ethylene and styrene are olefin compounds, but ethylbenzene is not because the only double bond present in ethylbenzene is a formal double bond that exists as part of an aromatic structure.

[0014] Now refer to Figure 1 The diagram shows a reactor system 100 that can be used with the methods of this disclosure, but other reactor systems that would be suitable for the methods of this disclosure are also contemplated. Figure 1 This is a simplified system, and other systems can be envisioned. Additionally, in... Figure 1 The present invention envisions various reactor types that are also potentially applicable to the methods described herein. For example, the oxygen carrier material disclosed herein can be used in at least the systems and methods disclosed in PCT International Application No. PCT / US23 / 73963 entitled “Methods For Dehydrogenating Hydrocarbons By Thermal Dehydrogenation” and International Patent Publication WO 2020 / 046978 entitled “Methods for Dehydrogenating Hydrocarbons,” the teachings of each of which are incorporated herein by reference in their entirety. These disclosed technical aspects may be further described herein with respect to… Figure 1 The methods and systems described. Also note, Figure 1 The steps shown should not be construed as necessary steps, especially with respect to the methods of the appended claims.

[0015] Still refer to Figure 1 The reactor system 100 may include a reactor 110 and a regeneration unit 120. In one or more embodiments, the reactor 110 may be a fluidized bed reactor. Generally, a feed stream 101 may be passed to and processed in the reactor 110 to form a product stream 102 comprising one or more olefin compounds. As described in detail herein, according to one or more embodiments, an oxygen carrier material may be circulated between the reactor 110 and the regeneration unit 120, wherein the oxygen carrier material enters the reactor 110 in an oxygen-enriched state, is supplied with oxygen in the reactor 110, leaves the reactor 110 in an oxygen-deficient state, and may be regenerated in the regeneration unit 120 to an oxygen-enriched state.

[0016] In one or more embodiments, feed stream 101 may comprise one or more hydrocarbons. As described herein, feed stream 101 may be passed to reactor 110. In one or more embodiments, the one or more hydrocarbons may comprise one or more of ethane, propane, butane, or ethylbenzene. According to one or more embodiments, the one or more hydrocarbons may comprise any one of at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of ethane. In another embodiment, the one or more hydrocarbons may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of propane. In another embodiment, the one or more hydrocarbons may comprise at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt%, or even at least 99 wt% of butane. In another embodiment, one or more hydrocarbons may contain at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, or even at least 99% by weight of ethylbenzene. In another embodiment, one or more hydrocarbons may contain at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, or even at least 99% by weight of the sum of ethane, propane, butane, and ethylbenzene.

[0017] According to the embodiment, the oxygen carrier material can be delivered to reactor 110 in an oxygen-enriched state. In reactor 110, one or more hydrocarbons in the feed stream 101 can be dehydrogenated to form hydrogen (i.e., gaseous H2) and one or more olefin compounds. According to the embodiment, at least a portion of the hydrogen can react with oxygen from the oxygen carrier material to form water. Reacting hydrogen with oxygen from the oxygen carrier material can reduce the oxygen carrier material and convert it to an oxygen-deficient state. As described herein, the oxygen-enriched oxygen carrier material has a greater amount of oxygen than the oxygen-deficient oxygen carrier material. However, it should be understood that some oxygen may still be contained in the oxygen-deficient oxygen carrier material.

[0018] According to some embodiments, the dehydrogenation reaction in reactor 110 can be thermally driven (i.e., non-catalytic), wherein in such embodiments, no dehydrogenation catalyst is used in reactor 110. While the temperature of reactor 110 is variable, in some embodiments, reactor 110 can be operated at temperatures from 600°C to 850°C, which may be suitable for promoting thermal dehydrogenation. In other embodiments, a dehydrogenation catalyst can be used to promote dehydrogenation in reactor 110. The dehydrogenation catalyst can be transferred together with the oxygen support material and circulated between reactor 110 and regeneration unit 120. In embodiments where a dehydrogenation catalyst is used, temperatures from 600°C to 850°C can also be utilized. Suitable dehydrogenation catalysts include, but are not limited to, those comprising platinum, platinum and gallium, platinum and tin, or chromium. For example, suitable catalysts are described in Chem. Rev. 2014, 114, 20, 10613–10653 (the entire contents of which are incorporated herein by reference) and U.S. Patent No. 8,669,406 (the entire contents of which are incorporated herein by reference).

[0019] One or more olefin compounds produced in reactor 110, along with unconverted hydrocarbons, water, and unconverted hydrogen, may exit reactor 110 via product stream 102. In one or more embodiments, the olefin compounds may include one or more of ethylene, propylene, butene, or styrene. The term butene includes any butene isomer, such as α-butene, cis-β-butene, trans-β-butene, and isobutene. In some embodiments, the olefin-containing effluent may contain at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, or even at least 60 wt% of ethylene. In other embodiments, the olefin-containing effluent may contain at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, or even at least 60 wt% of propylene. In other embodiments, the olefin-containing effluent may contain at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, or even at least 60 wt% of butene. In another embodiment, the olefin-containing effluent may contain at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, or even at least 60 wt% of styrene. In another embodiment, the olefin-containing effluent may contain at least 20 wt%, at least 30 wt%, at least 40 wt%, at least 50 wt%, or even at least 60 wt% of one or more of ethylene, propylene, butene, and styrene. Product stream 102 may further contain unreacted components from feed stream 101 and other reaction products that are not considered olefin compounds. Olefin compounds may be separated from the unreacted components in a subsequent separation step.

[0020] As described herein, in reactor 110, one or more hydrocarbons (such as ethane) can be dehydrogenated to produce hydrogen, which can then react with oxygen via a combustion reaction to form water. Oxygen is supplied by an oxygen carrier material, and the reaction of hydrogen to water pushes the dehydrogenation equilibrium toward the product, such as ethylene. In such embodiments, it is advantageous that the oxygen carrier material promotes the combustion of hydrogen more than its reaction with hydrocarbons present in reactor 110. Such hydrocarbons may include feed hydrocarbons (such as ethane) and product olefin compounds (such as ethylene). The reaction of these hydrocarbons with oxygen from the oxygen carrier material may undesirably form carbon monoxide and / or carbon dioxide. Carbon dioxide and carbon monoxide in product stream 102 can cause several problems, such as difficulty in separating such components from other compounds in product stream 102, and the potential release of carbon dioxide into the environment or the need to contain such carbon dioxide. For example, carbon monoxide may be an undesirable inhibitor in some downstream unit operations such as acetylene hydrogenation reactors. With this in mind, it has been found that the oxygen carrier material of this disclosure can have a relatively high selectivity for promoting the combustion of hydrogen to form water, compared to the selectivity for promoting the combustion of undesirable hydrocarbons with feed alkanes (such as ethane) and / or product olefin compounds (such as ethylene).

[0021] According to one or more embodiments, and as described herein, the hydrogen formed by the dehydrogenation reaction is gaseous H2, which reacts with oxygen from the oxygen-supported material. This is the opposite of some other reaction mechanisms in which hydrogen is not formed, such as oxidative dehydrogenation. Instead, in such oxidative dehydrogenation reactions, the alkane is processed into an alkene in a single reaction step, where no hydrogen (H2) is formed as an intermediate. This concept is described in detail, for example, in “Oxidative Dehydrogenation of Ethane: Common Principles and Mechanistic Aspects,” Gartner et al., ChemCatChem 2013, 5, 3196-3217.

[0022] As described herein, the oxygen carrier material is transferred into reactor 110 and subsequently exits reactor 110. See again... Figure 1In some embodiments, the oxygen carrier material circulates between reactor 110 and regeneration unit 120. The oxygen carrier material can be transferred from reactor 110 to regeneration unit 120 via feed stream 103 and back from regeneration unit 120 to reactor 110 via feed stream 104, and this circulation is continuous. Generally, the oxygen carrier material enters reactor 110 in an oxygen-enriched state, loses some or all of its oxygen atoms (to burn with hydrogen) in reactor 110, and leaves reactor 110 in an oxygen-deficient state via feed stream 103. The oxygen carrier material in the oxygen-deficient state can be transferred to regeneration unit 120, where it is exposed to oxygen and regenerated into its oxygen-enriched state. This oxygen-enriched oxygen carrier material can then be transferred back from regeneration unit 120 to reactor 110 via feed stream 104.

[0023] According to one or more embodiments, in regeneration unit 120, the oxygen carrier material may be exposed to oxygen, such as by exposure to air, oxygen-enriched air, or even pure oxygen. This exposure allows the oxygen carrier material to be replenished with oxygen. Additionally, in regeneration unit 120, fuel gas may be burned to heat the oxygen carrier material. This heat may be the primary heat source for maintaining the temperature in reactor 110, which uses heat for the dehydrogenation reaction. The fuel gas may include a variety of combustible compounds, such as hydrogen, methane, ethane, propane, etc. In some embodiments, methane may be the main component of the fuel gas. In embodiments, regeneration unit 120 may operate at elevated temperatures (such as 600°C to 900°C) or temperatures sufficient to heat the oxygen carrier material to such a temperature that it can be used to drive the dehydrogenation reaction in reactor 110.

[0024] As described herein, fuel gases (such as fuel gases containing methane) can be combusted in regeneration unit 120. According to some embodiments, it has been found that the composition of the oxygen carrier material can affect the combustion rate of the fuel gases. Therefore, it is undesirable to use oxygen carrier materials with compositions that would slow down hydrocarbon combustion. This is particularly problematic because oxygen carrier materials can be selected such that they promote hydrogen combustion in reactor 110 but not the combustion of alkanes and / or olefins. However, it has been observed that, according to one or more embodiments, the oxygen carrier materials of this disclosure can have an acceptable level of alkane combustion (such as methane combustion) promotion in regeneration unit 120, while exhibiting good hydrogen combustion selectivity relative to ethane combustion in reactor 110.

[0025] In some embodiments, the oxygen-enriched oxygen carrier material may be partially reduced before being delivered to reactor 110. This may include exposing the oxygen carrier material in stream 104 to a reducing gas, such as H2 and / or methane. Such treatment may allow some oxygen to be removed from the lattice of the oxygen carrier material. However, as disclosed herein, the amount of residual oxygen is still suitable for supplying oxygen to reactor 110 for hydrogen combustion.

[0026] In the embodiments disclosed herein, the oxygen carrier material may have a specific composition. As described herein, the oxygen carrier material may comprise a first composition and optionally one or more other materials. In one or more embodiments, the first composition may comprise or consist of active materials that generally contribute to oxygen carrying capacity of the oxygen carrier material described herein. As described below, such active materials may also affect fuel combustion during regeneration. Generally, in the embodiments described herein, at least 95% by weight of the first composition may consist of iron (Fe), one or more alkali metals, tungsten (W), oxygen (O), and optionally titanium (Ti), the amounts of which are defined by specific ratios between these various components.

[0027] In embodiments, in addition to the first composition, the oxygen carrier material may further comprise one or more additional materials. In embodiments, one or more additional materials may serve as binders in the oxygen carrier material. In some embodiments, the binder may not substantially contribute to the oxygen-carrying and / or catalytic function of the oxygen carrier material. The binder generally enhances the physical properties of the oxygen carrier material. According to embodiments, one or more additional materials may be selected from oxides of silicon, aluminum, calcium, magnesium, zirconium, niobium, or combinations thereof. Generally, one or more additional materials may not contain elements other than oxygen present in the first composition. Mixtures of various oxides of the intended elements may be included in one or more additional materials. Without limitation, in one or more embodiments, the additional materials may be selected from those disclosed in "Progress in Chemical-Looping Combustion and Reforming technologies" Progress in Energy and Combustion Science 38 (2012) 215-282 and "Chemical Looping Systems for Fossil Energy Conversions" by WILEY, Liang-Shih Fan, published in 2010. For example, in some embodiments, suitable other materials that can be used as binders include, but are not limited to, silica (colloidal, calcined, crystalline, amorphous), alumina (α, θ, or γ crystalline phase), and CaAl. x Oy MgAl2O4, zirconium oxide, inorganic clays (such as kaolin, other aluminum silicates) and glass materials (such as glass fiber).

[0028] According to one or more embodiments, the oxygen carrier material may comprise at least 75% by weight, at least 80% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, at least 99% by weight, at least 99.9% by weight of a first composition and a combination of one or more other materials, or may consist of a combination of the first composition and one or more other materials. For example, the oxygen carrier material may consist of a combination of the first composition and one or more other materials, wherein the one or more other materials may act as a binder and fill the remainder of the oxygen carrier material that is not part of the first composition.

[0029] In one or more embodiments, the oxygen carrier material may comprise a first composition in amounts of 1% to 5% by weight, 5% to 10% by weight, 10% to 15% by weight, 15% to 20% by weight, 20% to 25% by weight, 25% to 30% by weight, 30% to 35% by weight, 35% to 40% by weight, 40% to 45% by weight, 45% to 50% by weight, 50% to 55% by weight, 55% to 60% by weight, 60% to 65% by weight, 65% to 70% by weight, 70% to 75% by weight, 75% to 80% by weight, 80% to 85% by weight, 85% to 90% by weight, 90% to 95% by weight, 95% to 100% by weight, or any combination of one or more of these ranges. For example, the oxygen carrier material may comprise at least 5% by weight, at least 10% by weight, at least 15% by weight, at least 20% by weight, at least 25% by weight, at least 30% by weight, at least 35% by weight, at least 40% by weight, at least 45% by weight, at least 50% by weight, at least 55% by weight, at least 60% by weight, at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 85% by weight, at least 90% by weight, or even at least 95% by weight of the first composition. In some embodiments, the oxygen carrier material may comprise at least 99% by weight or at least 99.9% by weight of the first composition. In some embodiments, the oxygen carrier material may consist of the first composition.

[0030] In another embodiment, the oxygen carrier material may comprise one or more additional materials. According to the embodiment, the oxygen carrier material may comprise 1% to 50% by weight of one or more additional materials. For example, one or more additional materials may be present in the oxygen carrier material in amounts of 1% to 5% by weight, 5% to 10% by weight, 10% to 15% by weight, 15% to 20% by weight, 20% to 25% by weight, 25% to 30% by weight, 30% to 35% by weight, 35% to 40% by weight, 40% to 45% by weight, 45% to 50% by weight, or any combination of one or more of these ranges. For example, the oxygen carrier material may comprise less than or equal to 50% by weight and at least 5% by weight, at least 10% by weight, at least 15% by weight, at least 20% by weight, at least 25% by weight, at least 30% by weight, at least 35% by weight, at least 40% by weight, or at least 45% by weight of one or more additional materials. In another embodiment, the oxygen carrier material may comprise one or more other materials in amounts of at least 1% by weight and less than or equal to 5% by weight, less than or equal to 10% by weight, less than or equal to 15% by weight, less than or equal to 20% by weight, less than or equal to 25% by weight, less than or equal to 30% by weight, less than or equal to 35% by weight, less than or equal to 40% by weight, or less than or equal to 45% by weight.

[0031] As described herein, the relative amounts of materials in the first composition are described based on the relative amounts of atoms of each element contained in the first composition. Furthermore, as described herein, the oxygen-supporting material component can be described relative to the amounts of other components. For example, components described herein are expressed in amounts described as “molar parts.” As used herein, molar parts describe the molar ratio of one component to another and do not limit the total number or moles of a particular substituent. For example, iron may be present in an amount of 1 molar part, and oxygen may be present in amounts from 1 molar part to 10 molar parts, meaning that all compositions satisfying this ratio of iron atoms to oxygen atoms fall within the embodiments described herein, regardless of the original amounts of these components. Generally, and unless otherwise indicated, when multiple elements or other materials are listed together in specific amounts, this refers to the total of all such combinations of elements or other materials, even if it is not explicitly stated that the “total” or “combination” of these elements refers to the specified amount. For example, when “one or more alkali metals” are listed in amounts, the amount refers to the combination of all alkali metals.

[0032] Turning now to the first composition of the oxygen carrier material, in one or more embodiments, 95% by weight of the first composition may consist of: iron; one or more alkali metals; tungsten; oxygen; and optionally titanium. For example, at least 96% by weight, at least 97% by weight, at least 98% by weight, at least 99% by weight, at least 99.5% by weight, or at least 99.9% by weight of the first composition may consist of: iron; one or more alkali metals; tungsten; oxygen; and optionally titanium. In some embodiments, the first composition may consist of: iron; one or more alkali metals; tungsten; oxygen; and optionally titanium.

[0033] In one or more embodiments, iron may be present in the first composition, wherein iron is present in a relative amount of 1 mole part in the first composition. The amounts of other components are generally compared to 1 mole part of iron. Without being bound by any particular theory, it is believed that iron can serve as a major component, which binds to and dissociates from oxygen in redox reactions by altering its oxidation state.

[0034] In one or more embodiments, one or more alkali metals may be present in the first composition, wherein the one or more alkali metals may be present in the first composition in a relative amount of 0.04 moles to 0.8 moles. Without being bound by any particular theory, it is believed that the presence of this amount of alkali metal can improve hydrogen combustion selectivity relative to hydrocarbon combustion.

[0035] According to embodiments, one or more alkali metals may be selected from lithium, sodium, and potassium, wherein the relative amounts of the combination of lithium, sodium, and potassium are from 0.04 molar parts to 0.8 molar parts. In some embodiments, lithium is present in the first composition but sodium and potassium are absent. In other embodiments, sodium is present in the first composition but lithium and potassium are absent. In yet other embodiments, lithium and sodium are present in the first composition but potassium is absent, sodium and potassium are present in the first composition but lithium is absent, or potassium and lithium are present in the first composition but sodium is absent. In some embodiments, lithium, sodium, and potassium are present in the first composition.

[0036] In some embodiments, one or more alkali metals may be present in the first composition in a relative amount of less than or equal to 0.8 moles and at least 0.08 moles, at least 0.12 moles, at least 0.16 moles, at least 0.20 moles, at least 0.24 moles, at least 0.28 moles, at least 0.32 moles, at least 0.36 moles, at least 0.40 moles, at least 0.44 moles, at least 0.48 moles, at least 0.52 moles, at least 0.56 moles, at least 0.60 moles, at least 0.64 moles, at least 0.68 moles, at least 0.72 moles, or at least 0.76 moles.

[0037] In another embodiment, one or more alkali metals may be present in the first composition in a relative amount of at least 0.04 moles and less than or equal to 0.76 moles, less than or equal to 0.72 moles, less than or equal to 0.68 moles, less than or equal to 0.64 moles, less than or equal to 0.60 moles, less than or equal to 0.56 moles, less than or equal to 0.52 moles, less than or equal to 0.48 moles, less than or equal to 0.44 moles, less than or equal to 0.40 moles, less than or equal to 0.36 moles, less than or equal to 0.32 moles, less than or equal to 0.28 moles, less than or equal to 0.24 moles, less than or equal to 0.20 moles, less than or equal to 0.16 moles, less than or equal to 0.12 moles, or less than or equal to 0.08 moles.

[0038] In another embodiment, one or more alkali metals may be present in quantities of 0.04 mol to 0.08 mol, 0.08 mol to 0.12 mol, 0.12 mol to 0.16 mol, 0.16 mol to 0.20 mol, 0.20 mol to 0.24 mol, 0.24 mol to 0.28 mol, 0.28 mol to 0.32 mol, 0.32 mol to 0.36 mol, 0.36 mol to 0.40 mol, or 0.40 mol to 0.44 mol. The relative amounts of 0.44 to 0.48 moles, 0.48 to 0.52 moles, 0.52 to 0.56 moles, 0.56 to 0.60 moles, 0.60 to 0.64 moles, 0.64 to 0.68 moles, 0.68 to 0.72 moles, 0.72 to 0.76 moles, 0.76 to 0.80 moles, or any combination of one or more of these ranges, are present in the first composition.

[0039] In one or more embodiments, tungsten may be present in the first composition, wherein tungsten may be present in a relative amount of 0.02 molar parts to 0.4 molar parts in the first composition. Without being bound by theory, it is believed that tungsten present in this amount can modulate the release of oxygen from iron, which can inhibit the oxidation of hydrocarbons.

[0040] In some embodiments, tungsten may be present in the first composition in a relative amount of less than or equal to 0.4 moles and at least 0.06 moles, at least 0.08 moles, at least 0.10 moles, at least 0.12 moles, at least 0.14 moles, at least 0.16 moles, at least 0.18 moles, at least 0.20 moles, at least 0.22 moles, at least 0.24 moles, at least 0.26 moles, at least 0.28 moles, at least 0.30 moles, at least 0.32 moles, at least 0.34 moles, at least 0.36 moles, or even at least 0.38 moles.

[0041] In another embodiment, tungsten may be present in the first composition in a relative amount of at least 0.02 moles and less than or equal to 0.38 moles, less than or equal to 0.36 moles, less than or equal to 0.34 moles, less than or equal to 0.32 moles, less than or equal to 0.30 moles, less than or equal to 0.28 moles, less than or equal to 0.26 moles, less than or equal to 0.24 moles, less than or equal to 0.22 moles, less than or equal to 0.20 moles, less than or equal to 0.18 moles, less than or equal to 0.16 moles, less than or equal to 0.14 moles, less than or equal to 0.12 moles, less than or equal to 0.10 moles, less than or equal to 0.08 moles, less than or equal to 0.06 moles, or even less than or equal to 0.04 moles and at least 0.02 moles.

[0042] In another embodiment, tungsten can be in the amounts of 0.02 mol parts to 0.04 mol parts, 0.04 mol parts to 0.06 mol parts, 0.06 mol parts to 0.08 mol parts, 0.08 mol parts to 0.10 mol parts, 0.10 mol parts to 0.12 mol parts, 0.12 mol parts to 0.14 mol parts, 0.14 mol parts to 0.16 mol parts, 0.16 mol parts to 0.18 mol parts, 0.18 mol parts to 0.20 mol parts, and 0.20 mol parts to 0.22 mol parts. The first composition contains relative amounts of 0.22 to 0.24 moles, 0.24 to 0.26 moles, 0.26 to 0.28 moles, 0.28 to 0.30 moles, 0.30 to 0.32 moles, 0.32 to 0.34 moles, 0.34 to 0.36 moles, 0.36 to 0.38 moles, 0.38 to 0.40 moles, or any combination of one or more of these ranges.

[0043] In one or more embodiments, oxygen may be present in the first composition in a relative amount from 1 mole to 10 moles. The amount of oxygen may depend on the oxidation state of the oxygen support material, wherein more oxygen may be present in embodiments when the oxygen support material is storing oxygen atoms, and less oxygen may be present once such oxygen has been provided for the reaction and prior to regeneration. Generally, as described herein, the amount of oxygen may vary at different points in the process of forming the olefin.

[0044] In some embodiments, oxygen may be present in amounts less than or equal to 10 moles and at least 1.25 moles, at least 1.5 moles, at least 1.75 moles, at least 2 moles, at least 2.25 moles, at least 2.5 moles, at least 2.75 moles, at least 3 moles, at least 3.25 moles, at least 3.5 moles, at least 3.75 moles, at least 4 moles, at least 4.25 moles, at least 4.5 moles, at least 4.75 moles, at least 5 moles, at least 5.25 moles. The relative amounts of at least 5.5 moles, at least 5.75 moles, at least 6 moles, at least 6.25 moles, at least 6.5 moles, at least 6.75 moles, at least 7 moles, at least 7 moles, at least 7.25 moles, at least 7.5 moles, at least 7.75 moles, at least 8 moles, at least 8.25 moles, at least 8.5 moles, at least 8.75 moles, at least 9 moles, at least 9.25 moles, at least 9.5 moles, or even at least 9.75 moles are present in the first composition.

[0045] In another embodiment, oxygen may be at least 1 mole and less than or equal to 1.25 moles, less than or equal to 1.5 moles, less than or equal to 1.75 moles, less than or equal to 2 moles, less than or equal to 2.25 moles, less than or equal to 2.5 moles, less than or equal to 2.75 moles, less than or equal to 3 moles, less than or equal to 3.25 moles, less than or equal to 3.5 moles, less than or equal to 3.75 moles, less than or equal to 4 moles, less than or equal to 4.25 moles, less than or equal to 4.5 moles, less than or equal to 4.75 moles, less than or equal to 5 moles, less than or equal to 5.25 moles, less than or equal to... The relative amounts of 5.5 moles or less than or equal to 5.75 moles, 6 moles or less than or equal to 6.25 moles, 6.5 moles or less than or equal to 6.75 moles, 7 moles or less than or equal to 7.25 moles, 7.5 moles or less than or equal to 7.75 moles, 8 moles or less than or equal to 8.25 moles, 8.5 moles or less than or equal to 8.75 moles, 9 moles or less than or equal to 9.25 moles, 9.5 moles or less than or equal to 9.75 moles are present in the first composition.

[0046] In another embodiment, oxygen may be 1 mole to 1.25 moles, 1.25 moles to 1.5 moles, 1.5 moles to 1.75 moles, 1.75 moles to 2 moles, 2 moles to 2.25 moles, 2.25 moles to 2.5 moles, 2.5 moles to 2.75 moles, 2.75 moles to 3 moles, 3 moles to 3.25 moles, 3.25 moles to 3.5 moles, 3.5 moles to 3.75 moles, 3.75 moles to 4 moles, 4 moles to 4.25 moles, 4.25 moles to 4.5 moles, 4.5 moles to 4.75 moles, 4.75 moles to 5 moles, 5 moles to 5.25 moles, 5.25 moles to 5.5 moles, and 5.5 moles to 5. The relative amounts of 75 moles, 5.75 moles to 6 moles, 6 moles to 6.25 moles, 6.25 moles to 6.5 moles, 6.5 moles to 6.75 moles, 6.75 moles to 7 moles, 7 moles to 7.25 moles, 7.25 moles to 7.5 moles, 7.5 moles to 7.75 moles, 7.75 moles to 8 moles, 8 moles to 8.25 moles, 8.25 moles to 8.5 moles, 8.5 moles to 8.75 moles, 8.75 moles to 9 moles, 9 moles to 9.25 moles, 9.25 moles to 9.5 moles, 9.5 moles to 9.75 moles, 9.75 moles to 10 moles, or any combination of one or more of these ranges, are present in the first composition.

[0047] In one or more embodiments, the first composition may optionally contain titanium. That is, in some embodiments, titanium may be present in the first composition, and in other embodiments, titanium may not be present in the first composition. In one or more embodiments, titanium may be present in the first composition in a relative amount of 0 to 3 moles. In some embodiments, titanium may be present in the first composition in a relative amount of 0.001 to 3 moles. Without being bound by theory, it is believed that the presence of titanium can improve the mechanical stability of the oxygen-supported material. Furthermore, unlike ilmenite, titanium combined with iron and alkali metals can form crystalline phases containing alkali metals, iron, and titanium (e.g., prederite and alkali manganese ore), which may adversely promote reduction.

[0048] In some embodiments, titanium may be present in the first composition in a relative amount of at least 0.25 moles, at least 0.5 moles, at least 0.75 moles, at least 1 mole, at least 1.25 moles, at least 1.5 moles, at least 1.75 moles, at least 2 moles, at least 2.25 moles, at least 2.5 moles, or at least 2.75 moles and less than or equal to 3 moles.

[0049] In another embodiment, titanium may be present in the first composition in a relative amount of less than or equal to 0.25 moles, less than or equal to 0.5 moles, less than or equal to 0.75 moles, less than or equal to 1 mole, less than or equal to 1.25 moles, less than or equal to 1.5 moles, less than or equal to 1.75 moles, less than or equal to 2 moles, less than or equal to 2.25 moles, less than or equal to 2.5 moles, or less than or equal to 2.75 moles and at least 0 moles or at least 0.001 moles.

[0050] In another embodiment, titanium may be present in the first composition in relative amounts of 0 to 0.25 moles, 0.001 to 0.25 moles, 0.25 to 0.5 moles, 0.5 to 0.75 moles, 0.75 to 1 mole, 1 to 1.25 moles, 1.25 to 1.5 moles, 1.5 to 1.75 moles, 1.75 to 2 moles, 2 to 2.25 moles, 2.25 to 2.5 moles, 2.5 to 2.75 moles, 2.75 to 3 moles, or any combination of one or more of these ranges.

[0051] In one or more embodiments, the oxygen carrier material may be fluidizable. In some embodiments, the oxygen carrier material may have a median particle size (D50) of 50 µm to 300 µm, such as 50 µm to 250 µm, 50 µm to 200 µm, 50 µm to 150 µm, 50 µm to 100 µm, 100 µm to 300 µm, 100 µm to 250 µm, 100 µm to 200 µm, 100 µm to 150 µm, 150 µm to 300 µm, 150 µm to 250 µm, 150 µm to 200 µm, 200 µm to 300 µm, 200 µm to 250 µm, or 250 µm to 300 µm.

[0052] In some implementations, the oxygen carrier material may exhibit properties industrially known as “Geldart A” or “Geldart B” characteristics. The particles may be classified as “Group A” or “Group B” according to the following literature: D. Geldart, Gas Fluidization Technology, John Wiley & Sons (New York, 1986), 34-37; and D. Geldart, “Types of Gas Fluidization,” Powder Technol, 7 (1973) 285-292, the entire contents of which are incorporated herein by reference.

[0053] Group A is understood by those skilled in the art to represent an aeratable powder, having a range of bubble-free fluidization; high bed expansion; slow and linear degassing rate; bubble characteristics, which may include the advantage of splitting / coalescing bubbles, having a maximum bubble size and a large wake; a high level of solid mixing and gas backmixing, assuming U - umf are equal (U is the velocity of the carrier gas, and Umf is the minimum fluidization velocity, typically but not necessarily measured in meters per second (m / s), i.e., there is an excessive gas velocity); axisymmetric slug characteristics; and no spouting except in very shallow beds. The listed characteristics tend to improve with decreasing average particle size, assuming cfp is equal; or with increasing proportion < 45 micrometers (μm); or with increasing gas pressure, temperature, viscosity, and density. Generally, the particles may exhibit a small average particle size and / or a low particle density (< 1.4 grams per cubic centimeter, g / cm 3 ); are easily fluidized, where they fluidize smoothly at low gas velocities; and may exhibit controlled bubbling with small bubbles at higher gas velocities.

[0054] Group B is understood by those skilled in the art to represent "sand-like" powders, which start to bubble at Umf; which exhibit moderate bed expansion; rapid degassing; no limitation on bubble size; a moderate level of solid mixing and gas backmixing, assuming U - umf are equal; both axisymmetric and asymmetric slugs; and spouting only in shallow beds. These characteristics tend to improve with decreasing average particle size, but the particle size distribution and certain uncertainties in the gas, pressure, temperature, viscosity, or density seem to have little effect on improving these characteristics. Generally, when the density (pp) is 1.4 < pp < 4 g / cm 3 , the particle size (cfp) of most particles is 40 μm < cfp < 500 μm, and preferably, when the density (pp) is 4 g / cm 3 , the particle size of most particles is 60 μm < cfp < 500 μm, and when the density (pp) is 1 g / cm 3 , the particle size of most particles is 250 μm < cfp < 100 μm.

[0055] In one or more embodiments, the oxygen carrier material described herein can be prepared by a variety of synthetic techniques, including solid-state synthesis, or wet or dry impregnation followed by drying and high-temperature calcination, as known to those skilled in the art. Generally, the various components in the first composition can be added as solid powders in the form of their oxides, then thoroughly mixed or homogenized, followed by calcination in air at high temperature. Alternatively, some components in the first composition can be incorporated by completely (wet or dry impregnation) or partially (slurry impregnation) dissolving their precursors in water, and then combining them with the solid powders of the remaining components, followed by drying and high-temperature calcination in air. Optionally, small amounts of other materials described herein may be added during the synthesis of the oxygen carrier to provide physical strength and stability.

[0056] In some embodiments, as described above, the oxygen carrier can be prepared by impregnation. Impregnation can be performed using wet impregnation or dry impregnation (sometimes referred to as initial wetting impregnation). Impregnation can utilize an aqueous solution containing some components of the first composition; for example, in various embodiments, the aqueous solution may contain one or more precursors of alkali metals and / or tungsten. In some embodiments, the aqueous solution may contain potassium tungstate, potassium carbonate, potassium sulfate, potassium nitrate, potassium acetate, ammonium paratungstate, ammonium metatungstate, tungstic acid, or combinations thereof. In one or more embodiments, the aqueous solution may have a pH greater than 7. For example, the aqueous solution may have a pH greater than 7.5, greater than 8, greater than 8.5, greater than 9, greater than 9.5, greater than 10, greater than 10.5, greater than 11, or even greater than 11.5. In some embodiments, multiple impregnation steps may occur to impregnate different materials.

[0057] The impregnated material can then be dried after impregnation. In some embodiments, the impregnated material can be dried in air. In one or more embodiments, the impregnated material can be dried at temperatures below 200°C, such as below 175°C, below 150°C, below 125°C, below 100°C, below 75°C, or even below 50°C. In some embodiments, impregnation can be performed more than once with an aqueous solution, and the impregnated material can be dried between each impregnation.

[0058] The dried impregnated material can then be calcined to produce an oxygen carrier material. In one or more embodiments, calcination can be carried out at temperatures greater than 600°C, such as greater than 700°C, greater than 800°C, greater than 900°C, greater than 1000°C, greater than 1100°C, or even greater than 1200°C. In one or more embodiments, the dried impregnated material can be calcined in air. In embodiments utilizing multiple impregnation steps, the impregnated material can be calcined between each impregnation. In embodiments, the dried impregnated material can be calcined in air for more than 1 hour. For example, the dried impregnated material can be calcined in air for more than 2 hours, more than 4 hours, more than 10 hours, or even more than 20 hours.

[0059] In some embodiments, the oxygen carrier material can be used in methods including fluidized beds, moving beds, or circulating fluidized beds (CFB). In such embodiments, it may be desirable to have the oxygen carrier as engineered microparticles with "Geldart A" or "Geldart B" properties. Without being theoretically limited, in one or more embodiments, it is believed that a selection of methods for manufacturing engineered microparticles of the oxygen carrier material, such as manufacturing techniques like spray drying, high-shear granulation, and fluidized bed granulation, followed by drying and high-temperature calcination, can be used to achieve fluidizable microparticles.

[0060] This disclosure includes many aspects, including aspects 1 through 15 described herein.

[0061] Aspect 1. A method for producing an olefin compound, the method comprising: passing a feed stream into a reactor, wherein the feed stream comprises one or more hydrocarbons; passing an oxygen carrier material into the reactor, wherein in the reactor: dehydrogenating the one or more hydrocarbons to form hydrogen and one or more olefin compounds; and reacting at least a portion of the hydrogen with oxygen from the oxygen carrier material to produce water; wherein the oxygen carrier material comprises a first composition, wherein at least 95% by weight of the first composition comprises: 1 mole of iron; 0.04 to 0.8 moles of one or more alkali metals; 0.02 to 0.4 moles of tungsten; 0 to 3 moles of titanium; and 1 to 10 moles of oxygen.

[0062] Aspect 2. The method according to aspect 1, wherein the one or more hydrocarbons include ethane, ethylbenzene, propane, butane or combinations thereof; and the one or more olefin compounds include ethylene, styrene, propylene, butene or combinations thereof.

[0063] Aspect 3. The method according to any of the preceding aspects, wherein the oxygen carrier material is circulated between the reactor and the regeneration unit, wherein the oxygen carrier material leaving the reactor is in an oxygen-deficient state, and the oxygen carrier material leaving the regeneration unit is in an oxygen-rich state.

[0064] Aspect 4. The method according to aspect 3, wherein fuel gas is burned in the regeneration unit to heat the oxygen carrier material.

[0065] Aspect 5. The method according to aspect 4, wherein the fuel gas comprises hydrogen, methane, or a combination thereof.

[0066] Aspect 6. The method according to aspect 4, wherein the fuel gas comprises methane, ethane, propane, or combinations thereof.

[0067] Aspect 7. The method according to any of the preceding aspects, wherein the reactor is operated as a fluidized bed reactor.

[0068] Aspect 8. The method according to any of the preceding aspects, wherein the reactor is operated at a temperature of 600°C to 850°C.

[0069] Aspect 9. The method according to any of the preceding aspects, wherein no dehydrogenation catalyst is used in the dehydrogenation reactor.

[0070] Aspect 10. The method according to any of the preceding aspects, wherein the first composition comprises titanium.

[0071] Aspect 11. The method according to any of the preceding aspects, wherein the first composition does not contain titanium.

[0072] Aspect 12. The method according to any of the preceding aspects, wherein the first composition comprises: 1 mole of iron; 0.04 to 0.8 mole of one or more alkali metals; 0.02 to 0.4 mole of tungsten; 0 to 3 mole of titanium; and 1 to 10 mole of oxygen.

[0073] Aspect 13. The method according to any of the preceding aspects, wherein the oxygen carrier material further comprises one or more additional materials selected from oxides of silicon, aluminum, calcium, magnesium, zirconium, niobium, or combinations thereof.

[0074] Aspect 14. The method according to aspect 13, wherein the one or more additional materials are used as adhesives.

[0075] Aspect 15. The method according to aspect 13, wherein the oxygen carrier material comprises 1% to 50% by weight of the one or more other materials.

[0076] Example

[0077] Various embodiments of this disclosure will be further illustrated by the following examples. These examples are illustrative in nature and should not be construed as limiting the subject matter of this disclosure.

[0078] Example 1 - Sample Preparation

[0079] Comparative sample A was a non-redox reactive inert quartz sheet purchased from Pyromatics and sieved to 100-200 mesh before use.

[0080] Comparative sample B was tungsten oxide (WO3) commercially available from Sigma-Aldrich and sieved to 100-200 mesh before use.

[0081] Comparative sample C was prepared by first adding a small amount of water to ilmenite powder (Alfa Aesar) to form a paste. The paste was then transferred to an alumina crucible and calcined in air at 950°C for 6 hours.

[0082] Comparative samples C1, C2, and C4 were prepared as follows: stoichiometric amounts of K2CO3, NaNO3, Na2WO4, or ammonium metatungstate hydrate (Alfa Aesar) were dissolved in deionized water. The solution was then added to ilmenite powder (Alfa Aesar) to form a paste. The paste was thoroughly ground using a mortar and pestle, and then transferred to an alumina crucible and calcined in air at 950°C for 6 hours.

[0083] Comparative samples C3, C5, and C6 were prepared by thoroughly dry mixing stoichiometric amounts of WO3 or tungstic acid with ilmenite powder (Alfa Aesar), followed by the addition of a small amount of deionized water to form a paste. The paste was then thoroughly ground using a mortar and pestle and transferred to an alumina crucible, where it was calcined in air at 950°C for 6 hours.

[0084] Comparative samples C7 and C8 were prepared by thoroughly dry mixing stoichiometric amounts of K2WO4 (Alfa Aesar) with ilmenite powder (Alfa Aesar), followed by the addition of a small amount of deionized water to form a paste. The paste was then thoroughly ground using a mortar and pestle and transferred to an alumina crucible, where it was calcined in air at 950°C for 6 hours.

[0085] Comparative sample D was prepared as follows: First, stoichiometric amounts of Fe2O3 (Noah Technologies Corporation) and TiO2 (Sigma-Aldrich, 21 nm nanopowder) were weighed in a mortar and combined. The dry powder was ground with a pestle for 5 minutes. The powder was then shaken in a separate container for 1 minute and returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Subsequently, 5 to 10 mL of deionized water was added to the mortar, and the mixture was ground into a paste for 5 minutes. The paste was transferred to an alumina crucible and dried in air at 120 °C for at least 2 hours. The dried mixture was then calcined in air at 950 °C for 24 hours.

[0086] Comparative sample D1 was prepared as follows: First, stoichiometric amounts of powdered Fe₂O₃ and TiO₂ (Sigma-Aldrich, 21 nm nanoparticles) were weighed into a mortar. The dry powder was ground with a pestle for 5 minutes. The powder was then shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, stoichiometric amounts of powdered NaNO₃ were dissolved in approximately 10 mL of deionized water and added to the mortar. The mixture was ground into a paste for 5 minutes, then transferred to an alumina crucible and dried in air at 120 °C for at least 2 hours. The dried mixture was then calcined in air at 950 °C for 6 hours.

[0087] Comparative samples D2, D3, and D5 were prepared in the same manner as D1, using stoichiometric amounts of K2CO3, Fe2O3, and TiO2 as the initial powder mixture.

[0088] Comparative sample D4 was prepared as follows: First, stoichiometric amounts of powdered Fe₂O₃ and WO₃ (Sigma-Aldrich, < 25 μm) were weighed into a mortar. The dry powder was thoroughly ground with a pestle for 5 minutes. The powder was then shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Subsequently, 5 to 10 mL of deionized water was added to the mortar, and the mixture was ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried in air at 120°C for at least 2 hours. The dried mixture was then calcined in air at 950°C for 6 hours.

[0089] Comparative samples D6 and D7 were prepared in the same manner as comparative sample D2, using different stoichiometric amounts of K2CO3, Fe2O3, and TiO2.

[0090] Comparative sample D8 was prepared as follows: First, stoichiometric amounts of Fe₂O₃ and TiO₂ (Evonik, AEROXIDE P25) were weighed in a mortar. The dry powder was thoroughly ground with a pestle for 5 minutes. The powder was shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, a stoichiometric amount of powdered K₂WO₄ was dissolved in approximately 10 mL of deionized water. The alkaline solution was introduced into the mortar, and the mixture was ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried in air at 120°C for at least 2 hours. The dried mixture was then calcined in air at 950°C for 24 hours.

[0091] Comparative samples E, F, and G were all prepared in the same manner as comparative sample D, with calcination temperatures of 800℃, 850℃, and 900℃, respectively.

[0092] Comparative sample H was prepared in the same manner as comparative sample D4, except that ammonium metatungstate ((NH4)6H2W) was used. 12 O 40 xH2O (Sigma-Aldrich) replaces WO3.

[0093] Comparative sample I was prepared as follows: First, stoichiometric amounts of Fe₂O₃ (Noah Chemicals) and TiO₂ (Evonik, AEROXIDE P25) were thoroughly dry-mixed. The powdered mixture was then transferred to a mortar. In a separate vial, stoichiometric amounts of ammonium metatungstate hydrate (Alfa Aesar) were dissolved in deionized water. The solution was added dropwise to the powdered mixture to form a paste, which was then thoroughly ground and transferred to an alumina crucible. The sample was heated to 90°C for at least 2 hours and then calcined in air at 950°C for 6 hours.

[0094] Comparative sample J was prepared as follows: First, stoichiometric amounts of Fe₂O₃ (Noah Chemicals) and TiO₂ (Evonik, AEROXIDE P25) were thoroughly dry-mixed. The powdered mixture was then transferred to a mortar. In a separate vial, a stoichiometric amount of K₂CO₃ (Alfa Aesar) was dissolved in deionized water. The solution was added dropwise to the powdered mixture to form a paste, which was thoroughly ground and then transferred to an alumina crucible. The sample was heated to 90°C for at least 2 hours and then calcined in air at 950°C for 6 hours.

[0095] Samples 1 to 3 were prepared as follows: First, stoichiometric amounts of K2WO4 (Alfa Aesar) were thoroughly dry-mixed with ilmenite powder. Then, a small amount of deionized water was added to form a paste. The paste was thoroughly ground using a mortar and pestle, and then transferred to an alumina crucible and calcined in air at 950°C for 6 hours.

[0096] Sample 4 was prepared by dissolving stoichiometric amounts of K₂CO₃, NaNO₃, Na₂WO₄, or ammonium metatungstate hydrate (Alfa Aesar) in deionized water. The solution was then added to ilmenite powder (Alfa Aesar) to form a paste. The paste was thoroughly ground using a mortar and pestle and then transferred to an alumina crucible and calcined in air at 950°C for 6 hours.

[0097] Samples 5 through 7 were prepared in the same manner as comparative sample D8, using different stoichiometric amounts of K2WO4, Fe2O3, and TiO2 (Evonik, AEROXIDE P25). In this case, K2WO4 was not completely soluble in approximately 10 mL of deionized water, and the entire slurry was incorporated into the dry powder mixture.

[0098] Sample 8 was prepared as follows: First, stoichiometric amounts of Fe₂O₃ and TiO₂ (Evonik, AEROXIDE P25) were weighed into a mortar. The dry powder was thoroughly ground with a pestle for 5 minutes. The powder was shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, stoichiometric amounts of powdered K₂WO₄ and K₂CO₃ were dissolved in approximately 10 mL of deionized water. The alkaline solution was then introduced into the mortar containing the mixed metal oxide powders, and the mixture was thoroughly ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried in air at 120°C for at least 2 hours. The dried mixture was then calcined in air at 950°C for 6 hours.

[0099] Sample 9 was prepared in the same manner as Sample 8, using different stoichiometric amounts of K2WO4, K2CO3, Fe2O3 and TiO2 (Evonik, AEROXIDE P25).

[0100] Samples 10 and 11 were prepared in the same manner as sample 8, using different stoichiometric amounts of K2WO4, K2CO3 and FeTiO3.

[0101] Samples 12 and 13 were prepared by adding stoichiometric amounts of Fe2O3 (Noah Chemicals), TiO2 (Evonik, AEROXIDE P25), and K2WO4 to a mortar, thoroughly mixing the dry powders, and then adding a small amount of water to form a paste. The paste was transferred to an alumina crucible and calcined at 950°C for at least 6 hours.

[0102] Samples 14 and 15 were prepared as follows: Fe₂O₃ with different particle sizes were first obtained commercially from two different suppliers. Stoichiometric amounts of Fe₂O₃ and K₂WO₄ were thoroughly mixed in a mortar. A small amount of water was added to form a paste. The paste was then transferred to an alumina crucible and calcined at 950°C for at least 6 hours.

[0103] Sample 16 was prepared in the same manner as Sample 2.

[0104] Sample 17 was prepared as follows: First, a stoichiometric amount of K₂WO₄ was completely dissolved in a small amount of deionized water at room temperature. Ilmenite powder was added to an alumina crucible, and the alkaline solution was transferred to the crucible. The slurry was thoroughly mixed before calcination. The slurry was then transferred to an alumina crucible to dry at 90°C for at least 6 hours, and calcined in air at 950°C for 6 hours.

[0105] Sample 18 was prepared by first completely dissolving 16 individual K2WO4 impregnations in deionized water. The amount of water required to form a paste with the ilmenite powder was empirically determined to determine the minimum number of individual impregnations needed to achieve the total stoichiometry of K2WO4. After each impregnation, the paste was heated from room temperature to 90°C over 30 minutes and held at 90°C for 3 hours to dry completely before the next impregnation. After the 16th impregnation, the sample was calcined at 950°C for 6 hours.

[0106] Sample 19 was prepared as follows: First, stoichiometric amounts of Fe₂O₃, TiO₂ (Evonik, AEROXIDE P25), and WO₃ (Sigma-Aldrich, < 25 μm) were weighed in a mortar. The dry powder was thoroughly ground with a pestle for 5 minutes. The powder was then shaken in a separate container for 1 minute and returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, stoichiometric amounts of powdered K₂CO₃ were dissolved in approximately 10 mL of deionized water. The alkaline solution was then introduced into the mortar containing the mixed metal oxide powders, and the mixture was thoroughly ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried in air at 120°C for at least 2 hours. The dried mixture was then calcined in air at 950°C for 6 hours.

[0107] Sample 20 was prepared in the same manner as Sample 19, using different stoichiometric amounts of K2CO3, WO3, Fe2O3 and TiO2 (Evonik, AEROXIDE P25).

[0108] Sample 21 was prepared in the same manner as Sample 20, but using a different TiO2 source (Noah Technologies Corporation, anatase).

[0109] Sample 22 was prepared as follows: First, stoichiometric amounts of Fe₂O₃, FeTiO₃ (Thermoscientific), and WO₃ were weighed in a mortar. The dry powder was thoroughly ground with a pestle for 5 minutes. The powder was shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, stoichiometric amounts of powdered K₂CO₃ were dissolved in approximately 10 mL of deionized water. The alkaline solution was then introduced into the mortar containing the mixed metal oxide powders, and the mixture was thoroughly ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried in air at 120°C for at least 2 hours. The dried mixture was then calcined in air at 950°C for 6 hours.

[0110] Sample 23 was prepared in the same manner as sample 22, using different stoichiometric amounts of K2CO3, WO3, Fe2O3 and FeTiO3.

[0111] Samples 24 and 25 were prepared as follows: First, a stoichiometric amount of ammonium metatungstate hydrate was dissolved in deionized water. The solution was then added dropwise to a pre-calcined sample K to form a paste. The paste was then dried in an alumina crucible at 90°C for 2 hours and subsequently calcined in air at 950°C for 6 hours.

[0112] Sample 26 was prepared as follows: First, a stoichiometric amount of K₂CO₃ was dissolved in deionized water. Then, the solution was added dropwise to a pre-calcined sample L to form a paste. The paste was then dried in an alumina crucible at 90°C for 2 hours and then calcined in air at 950°C for 6 hours.

[0113] Sample 27 was prepared as follows: First, stoichiometric amounts of Fe₂O₃ (Noah Chemicals) and TiO₂ (Evonik, AEROXIDE P25) were dry-mixed in a mortar. In two separate vials, stoichiometric amounts of K₂CO₃ and ammonium metatungstate hydrate were dissolved in deionized water. Each solution was then added dropwise to the dry mixed metal oxide powder to form a paste, which was thoroughly ground. The paste was then transferred to an alumina crucible and dried at 90°C for 2 hours, followed by calcination in air at 950°C for 6 hours.

[0114] Example 2 - Selective Hydrogen Combustion Performance

[0115] The selective hydrogen combustion performance of samples was evaluated in a U-shaped fixed-bed reactor made of quartz. First, 125 mg of sample was sized to 100–200 mesh and diluted with 400 mg of quartz flakes (100–200 mesh) before being loaded into the reactor. Once loaded, the upstream empty space was filled with 18–35 mesh quartz flakes. The sample was then heated to 750 °C under air flow, purged with helium, and subjected to three cycles at 750 °C at a total gas flow rate of 12 standard cubic centimeters (sccm). In each cycle, the sample was first exposed to 90% ethane / 10% nitrogen for 1 minute, purged with helium, and then regenerated in air for 15 minutes. After 23 seconds of ethane exposure, the effluent gas composition was analyzed by gas chromatography. For each oxygen carrier, three parallel reduction-oxidation cycles were performed, and the average ethane conversion, ethylene selectivity, and CO2 were reported at the 50th cycle. x Selectivity and the ratio of hydrogen to ethylene.

[0116] The ethane conversion and carbon-based selectivity are calculated using the following equations, where [X] corresponds to the mole fraction and [IS] corresponds to the internal standard.

[0117]

[0118] Table 1: Selective hydrogen combustion performance of materials evaluated using the method of Example 2

[0119]

[0120] As shown in Table 1, compared with samples without alkali metals, tungsten, or both, the addition of both alkali metals (potassium or sodium) and tungsten improved ethylene selectivity and reduced CO2. xSelectivity. Samples lacking either alkali metals or tungsten (i.e., comparative sample C) exhibited worse ethylene selectivity than samples containing only alkali metals (i.e., comparative samples C1 and C2), samples containing only tungsten (i.e., comparative samples C3 to C6), and samples containing both alkali metals and tungsten (i.e., samples 1 to 3). This indicates that the presence of alkali metals, tungsten, and especially both improves ethylene selectivity. Furthermore, samples containing both alkali metals and tungsten showed significantly improved CO2 selectivity compared to samples lacking both alkali metals and tungsten. x Selectivity. For example, samples 1 to 3 have 0.6% or less CO. x Selectivity, while comparison sample C has 5.2% CO. x Selectivity.

[0121] Samples containing both alkali metals and tungsten also exhibited significantly improved hydrogen-to-ethylene ratios compared to samples containing only one or neither of these metals. For example, samples 1 to 3 containing both potassium and tungsten had H₂ / C₂H₄ ratios less than 0.50, while comparative samples C to C8 had H₂ / C₂H₄ ratios greater than 0.50. This indicates that the presence of potassium and tungsten improves the selective combustion of hydrogen in the reactor.

[0122] The ethylene selectivity and CO can be seen throughout Table 1. x The same improvement in selectivity and H2 / C2H4 ratio. For example, comparative sample D, which does not contain alkali metals or tungsten, has ethylene selectivity 5 to 15 worse than samples containing potassium and tungsten, and CO2 selectivity. x Selectivity and H2 / C2H4 ratio. Therefore, Table 1 indicates that, in addition to iron, the presence of both alkali metals and tungsten improves the selectivity of hydrogen combustion relative to hydrocarbons, resulting in lower CO levels. x This formation significantly improves ethylene selectivity and CO2 selectivity. x Selectivity and / or H2 / C2H4 ratio.

[0123] Table 2: Selective hydrogen combustion performance of materials evaluated using the method of Example 2

[0124]

[0125] As shown in Table 2, samples containing alkali metals (potassium) and tungsten (i.e., samples 16 to 18) exhibited better H2 / C2H4 ratios than samples without potassium and tungsten (i.e., comparative samples E to H). For example, sample 16 had an H2 / C2H4 ratio of 0.3, while comparative sample E had an H2 / C2H4 ratio of 0.62. Furthermore, samples containing potassium and tungsten showed significantly improved CO2 content compared to samples without potassium and tungsten. x Selectivity. For example, samples 16 to 18 had 0.4% to 0.6% CO. x Selectivity, while comparative samples E to G, which do not contain potassium or tungsten, have a CO content greater than 13%.x Selectivity. Furthermore, comparison with sample H indicates that adding only tungsten will reduce CO... x Selectivity was improved to only 5.5%. Therefore, compared to samples without alkali metals or tungsten or with only one of alkali metals or tungsten, the presence of both alkali metals and tungsten in the oxygen support material resulted in a significantly improved CO2 selectivity. x Selectivity.

[0126] Table 2 also indicates that the presence of potassium and tungsten improves C2H4 selectivity. For example, comparative sample E has a C2H4 selectivity of 77.3%, and sample 18 has a C2H4 selectivity of 95.0%. The H2 / C2H4 ratio is also improved, as indicated by sample 16 with an H2 / C2H4 ratio of 0.3 and comparative sample E with an H2 / C2H4 ratio of 0.62.

[0127] Example 3 - Selective Hydrogen Combustion Performance

[0128] The oxygen carrier was tested in a fixed-bed laboratory reactor. A 0.5 g sample portion was loaded into a 0.5-inch OD quartz sphere connected to a 6.5 mm outer diameter (OD) quartz tube. The sample bed was supported on a piece of quartz wool and a layer of 0.5 mm to 1.0 mm quartz sheet. The reactor was mounted in a flip-top furnace, and a 50 sccm flow of helium was introduced through the reactor tubes. The reactor was then heated from room temperature to 780°C at a 50 sccm flow. The oxygen carrier material was subjected to several cycles. Each cycle consisted of ethane dehydrogenation, a first regeneration in air, fuel combustion, and then a second regeneration in air, purged with inert helium in the reaction tubes between reduction and oxidation pulses. The ethane dehydrogenation step was performed over 5.3 hours. -1 The reaction was carried out at a gravity hourly space velocity (WHSV). Specifically, a gas mixture containing 90 mol% ethane and 10 mol% helium was fed through the reactor at 40 sccm for 60 seconds while the reactor was maintained at 780°C. The composition of the product gas was analyzed midway through the 30-second pulse of the dehydrogenation reaction. During the first regeneration step in air, air was fed through the reactor at 40 sccm for 2 minutes. The fuel combustion step was carried out at 0.079 hr. -1The WHSV was used. Specifically, a gas mixture containing 2.5 mol% methane, 9 mol% oxygen, and the balance nitrogen was fed through the reactor at 40 sccm for 180 seconds while the reactor was maintained at 780°C. The composition of the product gas was analyzed 60 seconds into the fuel combustion pulse. Finally, 40 sccm of air was fed through the reactor for 4 minutes for a second air regeneration step. The composition of the product gas was analyzed using a Siemens Maxim process gas chromatograph. For each oxygen carrier material, multiple parallel reduction-oxidation cycles were performed, and the average ethane conversion, ethylene selectivity, and CO2 were reported. x Selectivity and the ratio of hydrogen to ethylene.

[0129] Table 3: Selective hydrogen combustion performance of materials evaluated using the method of Example 3

[0130]

[0131] As shown in Table 3, the presence of additional promoters such as potassium and tungsten (i.e., samples 19 to 23) significantly improved C2H4 selectivity compared to oxygen carriers without those additional promoters (i.e., comparison sample D). For example, samples with A 0.26 and W 0.13 Sample 19 exhibited 95.2% ethylene selectivity, while comparative sample D, lacking both K and W, showed 77.0% ethylene selectivity. Furthermore, the presence of both potassium and tungsten improved the hydrogen-to-ethylene ratio. Comparative sample D had an H2 / C2H4 ratio of 0.37, while samples 19 through 23 had H2 / C2H4 ratios of 0.2 or less.

[0132] The presence of both potassium and tungsten (i.e., samples 24 to 27) significantly improved C2H4 selectivity compared to samples containing only potassium (i.e., comparative sample J) or only tungsten (i.e., comparative sample I). For example, samples without A and W... 0.12 Comparative sample I has 91% C2H4 selectivity and possesses A 0.22 Furthermore, the comparative sample J, lacking potassium (W), exhibited a 28% C2H6 conversion and 84.9% C2H4 selectivity. Sample 25, containing both potassium and tungsten, demonstrated a 25.7% C2H6 conversion and 95.4% C2H4 selectivity. Additionally, the presence of both potassium and tungsten significantly improved CO2 conversion. x Selectivity and hydrogen to ethylene ratio. For example, comparing samples D, I, and J, which have CO ratios of 17.1%, 5.9%, and 10.6%, respectively. x Selectivity, while all samples 19 to 27 had 1.8% or less CO. x Selectivity.

[0133] It will be apparent to those skilled in the art that various modifications and variations can be made to the technology disclosed herein without departing from the spirit and scope of this invention. Because modifications, combinations, sub-combinations, and variations of the disclosed embodiments can be made by those skilled in the art that incorporate the spirit and essence of the technology disclosed herein, this technology should be construed as including all things within the scope of the appended claims and their equivalents. Furthermore, although some aspects of this disclosure may be identified herein as preferred or particularly advantageous, this disclosure is not limited to these aspects upon consideration.

[0134] It should be noted that the various details described in this disclosure should not be construed as implying that such details relate to elements that are fundamental components of the various embodiments described in this disclosure, even where specific elements are shown in each of the accompanying drawings. Unless so expressly stated, none of the features disclosed and described herein should be interpreted as "essential." The embodiments considered in this art include those that include some or all of the features of the appended claims.

[0135] For the purposes of describing and defining this disclosure, it should be noted that the term "about" is used in this disclosure to indicate an inherent uncertainty attributable to any quantitative comparison, value, measurement, or other representation. The term "about" is also used in this disclosure to indicate the degree to which a quantitative representation may vary from a specified reference without causing a change in the essential function of the subject matter of interest.

[0136] In relevant contexts, where a composition is described as "comprising" one or more elements, embodiments of compositions "composed of" or "substantially composed of" those one or more elements are considered herein.

[0137] It should be understood that, in some embodiments, the composition range of a chemical component in a stream or reactor should be understood as a mixture containing isomers of that component. For example, specifying the composition range of butene may include a mixture of various isomers of butene. It should be understood that the embodiments provide composition ranges for various streams, and the total amount of isomers of a particular chemical composition may constitute a range.

[0138] It should be noted that one or more of the following claims and detailed descriptions utilize the term "where (or wherever)" as a transitional phrase. For the purpose of defining this technology, it should be noted that this term is introduced in the claims as an open transitional phrase used to introduce a description of a series of characteristics of the structure, and should be interpreted in a manner similar to the more commonly used open prepositional term "comprising".

[0139] It should be understood that any two quantitative values ​​assigned to a characteristic can constitute a range for that characteristic, and all combinations of ranges formed by all stated quantitative values ​​of a given characteristic are considered in this disclosure. Where multiple ranges of quantitative values ​​are provided, these ranges can be combined to form a wider range, as is considered in the embodiments described herein.

[0140] As understood in the context of the terminology used herein, the term "transfer" can include the direct transfer of matter between two parts of the disclosed system, and in some cases, it means the indirect transfer of matter between two parts of the disclosed system. For example, indirect transfer can include the step of said matter transfer via intermediate operating units, valves, sensors, etc.

Claims

1. A method for producing an olefin compound, the method comprising: A feed stream is passed into the reactor, wherein the feed stream contains one or more hydrocarbons; The oxygen carrier material is transferred into the reactor, wherein in the reactor: To dehydrogenate one or more hydrocarbons to form hydrogen gas and one or more olefin compounds; as well as At least a portion of the hydrogen gas is reacted with oxygen from the oxygen carrier material to produce water; The oxygen carrier material comprises a first composition, wherein at least 95% by weight of the first composition consists of the following: 1 mole of iron; 0.04 molar to 0.8 molar of one or more alkali metals; 0.02 to 0.4 moles of tungsten; 0 to 3 moles of titanium; and 1 to 10 moles of oxygen.

2. The method according to claim 1, wherein: The one or more hydrocarbons include ethane, ethylbenzene, propane, butane, or combinations thereof; and The one or more olefin compounds include ethylene, styrene, propylene, butene, or combinations thereof.

3. The method according to any of the preceding claims, wherein the oxygen carrier material is circulated between the reactor and the regeneration unit, wherein the oxygen carrier material leaving the reactor is in an oxygen-deficient state, and the oxygen carrier material leaving the regeneration unit is in an oxygen-rich state.

4. The method of claim 3, wherein fuel gas is burned in the regeneration unit to heat the oxygen carrier material.

5. The method of claim 4, wherein the fuel gas comprises hydrogen, methane, or a combination thereof.

6. The method of claim 4, wherein the fuel gas comprises methane, ethane, propane, or a combination thereof.

7. The method according to any of the preceding claims, wherein the reactor is operated as a fluidized bed reactor.

8. The method according to any of the preceding claims, wherein the reactor is operated at a temperature of 600°C to 850°C.

9. The method according to any of the preceding claims, wherein no dehydrogenation catalyst is used in the dehydrogenation reactor.

10. The method according to any of the preceding claims, wherein the first composition comprises titanium.

11. The method according to any of the preceding claims, wherein the first composition does not contain titanium.

12. The method according to any preceding claim, wherein the first composition comprises: 1 mole of iron; 0.04 molar to 0.8 molar of one or more alkali metals; 0.02 to 0.4 moles of tungsten; 0 to 3 moles of titanium; as well as 1 to 10 moles of oxygen.

13. The method according to any of the preceding claims, wherein the oxygen carrier material further comprises one or more additional materials selected from oxides of silicon, aluminum, calcium, magnesium, zirconium, niobium, or combinations thereof.

14. The method of claim 13, wherein the one or more additional materials are used as an adhesive.

15. The method of claim 13, wherein the oxygen carrier material comprises 1% to 50% by weight of one or more of the other materials.

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